Short-Term Credit Arrangements and Borrowings (Tables)

3 Months Ended

Mar. 31, 2018

Short-term Debt [Abstract]

Schedule of Line of Credit Facilities

The availability under the facilities in place at March 31, 2018 is shown in the following table:

	DTE Energy		DTE Electric		DTE Gas		Total
	(In millions)
Unsecured letter of credit facility, expiring in February 2019	$	150	$	—	$	—	$	150
Unsecured letter of credit facility, expiring in September 2019	70		—		—		70
Unsecured revolving credit facility, expiring April 2022	1,200		400		300		1,900
	1,420		400		300		2,120
Amounts outstanding at March 31, 2018
Commercial paper issuances	—		380		255		635
Letters of credit	221		—		—		221
	221		380		255		856
Net availability at March 31, 2018	$	1,199	$	20	$	45	$	1,264